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source: palm/trunk/SOURCE/random_generator_parallel_mod.f90 @ 1949

Last change on this file since 1949 was 1851, checked in by maronga, 9 years ago
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[1850]	1	!> @file random_generator_parallel_mod.f90
[1400]	2	!------------------------------------------------------------------------------!
	3	! This file is part of PALM.
	4	!
	5	! PALM is free software: you can redistribute it and/or modify it under the terms
	6	! of the GNU General Public License as published by the Free Software Foundation,
	7	! either version 3 of the License, or (at your option) any later version.
	8	!
	9	! PALM is distributed in the hope that it will be useful, but WITHOUT ANY
	10	! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
	11	! A PARTICULAR PURPOSE. See the GNU General Public License for more details.
	12	!
	13	! You should have received a copy of the GNU General Public License along with
	14	! PALM. If not, see <http://www.gnu.org/licenses/>.
	15	!
[1818]	16	! Copyright 1997-2016 Leibniz Universitaet Hannover
[1400]	17	!------------------------------------------------------------------------------!
	18	!
	19	! Current revisions:
	20	! -----------------
	21	!
[1683]	22	!
[1400]	23	! Former revisions:
	24	! -----------------
	25	! $Id: random_generator_parallel_mod.f90 1851 2016-04-08 13:32:50Z maronga $
	26	!
[1851]	27	! 1850 2016-04-08 13:29:27Z maronga
	28	! Module renamed
	29	!
	30	!
[1683]	31	! 1682 2015-10-07 23:56:08Z knoop
	32	! Code annotations made doxygen readable
	33	!
[1401]	34	! 1400 2014-05-09 14:03:54Z knoop
	35	! Initial revision
	36	!
[1400]	37	!
	38	! Description:
	39	! ------------
[1682]	40	!> This module contains and supports the random number generating routine ran_parallel.
	41	!> ran_parallel returns a uniform random deviate between 0.0 and 1.0
	42	!> (exclusive of the end point values).
	43	!> Additionally it provides the generator with five integer for use as initial state space.
	44	!> The first tree integers (iran, jran, kran) are maintained as non negative values,
	45	!> while the last two (mran, nran) have 32-bit nonzero values.
	46	!> Also provided by this module is support for initializing or reinitializing
	47	!> the state space to a desired standard sequence number, hashing the initial
	48	!> values to random values, and allocating and deallocating the internal workspace
	49	!> Random number generator, produces numbers equally distributed in interval
	50	!>
	51	!> This routine is taken from the "numerical recipies vol. 2"
[1400]	52	!------------------------------------------------------------------------------!
[1682]	53	MODULE random_generator_parallel
	54
[1400]	55
	56	USE kinds
	57
	58	IMPLICIT NONE
	59
	60	PRIVATE
	61	PUBLIC random_number_parallel, random_seed_parallel, random_dummy, &
	62	id_random_array, seq_random_array
	63
[1682]	64	INTEGER(isp), SAVE :: lenran=0 !<
	65	INTEGER(isp), SAVE :: seq=0 !<
	66	INTEGER(isp), SAVE :: iran0 !<
	67	INTEGER(isp), SAVE :: jran0 !<
	68	INTEGER(isp), SAVE :: kran0 !<
	69	INTEGER(isp), SAVE :: mran0 !<
	70	INTEGER(isp), SAVE :: nran0 !<
	71	INTEGER(isp), SAVE :: rans !<
[1400]	72
[1682]	73	INTEGER(isp), DIMENSION(:, :), POINTER, SAVE :: ranseeds !<
[1400]	74
[1682]	75	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: iran !<
	76	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: jran !<
	77	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: kran !<
	78	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: mran !<
	79	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: nran !<
	80	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: ranv !<
[1400]	81
	82
	83
[1682]	84	INTEGER(isp), DIMENSION(:,:), ALLOCATABLE :: id_random_array !<
	85	INTEGER(isp), DIMENSION(:,:,:), ALLOCATABLE :: seq_random_array !<
[1400]	86
[1682]	87	REAL(wp), SAVE :: amm !<
[1400]	88
[1682]	89	REAL(wp) :: random_dummy=0.0 !<
[1400]	90
	91	INTERFACE random_number_parallel
	92	MODULE PROCEDURE ran0_s
	93	END INTERFACE
	94
	95	INTERFACE random_seed_parallel
	96	MODULE PROCEDURE random_seed_parallel
	97	END INTERFACE
	98
	99	INTERFACE ran_hash
	100	MODULE PROCEDURE ran_hash_v
	101	END INTERFACE
	102
	103	INTERFACE reallocate
	104	MODULE PROCEDURE reallocate_iv,reallocate_im
	105	END INTERFACE
	106
	107	INTERFACE arth
	108	MODULE PROCEDURE arth_i
	109	END INTERFACE
	110
	111	CONTAINS
	112
	113	!------------------------------------------------------------------------------!
	114	! Description:
	115	! ------------
[1682]	116	!> Lagged Fibonacci generator combined with a Marsaglia shiftsequence.
	117	!> Returns as harvest a uniform random deviate between 0.0 and 1.0 (exclusive of the end point values).
	118	!> This generator has the same calling and initialization conventions as Fortran 90's random_number routine.
	119	!> Use random_seed_parallel to initialize or reinitialize to a particular sequence.
	120	!> The period of this generator is about 2.0 x 10^28, and it fully vectorizes.
	121	!> Validity of the integer model assumed by this generator is tested at initialization.
[1400]	122	!------------------------------------------------------------------------------!
	123	SUBROUTINE ran0_s(harvest)
	124
	125	USE kinds
	126
	127	IMPLICIT NONE
	128
[1682]	129	REAL(wp), INTENT(OUT) :: harvest !<
[1400]	130
	131	IF (lenran < 1) CALL ran_init(1) !- Initialization routine in ran_state.
	132
	133	!- Update Fibonacci generator, which has period p^2 + p + 1, p = 2^31 - 69.
	134	rans = iran0 - kran0
	135
	136	IF (rans < 0) rans = rans + 2147483579_isp
	137
	138	iran0 = jran0
	139	jran0 = kran0
	140	kran0 = rans
	141
	142	nran0 = ieor( nran0, ishft (nran0, 13) ) !- Update Marsaglia shift sequence with period 2^32 - 1.
	143	nran0 = ieor( nran0, ishft (nran0, -17) )
	144	nran0 = ieor( nran0, ishft (nran0, 5) )
	145
	146	rans = ieor( nran0, rans ) !- Combine the generators.
	147
	148	harvest = amm * merge( rans, not(rans), rans < 0 ) !- Make the result positive definite (note that amm is negative).
	149
	150	END SUBROUTINE ran0_s
	151
	152	!------------------------------------------------------------------------------!
	153	! Description:
	154	! ------------
[1682]	155	!> Initialize or reinitialize the random generator state space to vectors of size length.
	156	!> The saved variable seq is hashed (via calls to the module routine ran_hash)
	157	!> to create unique starting seeds, different for each vector component.
[1400]	158	!------------------------------------------------------------------------------!
	159	SUBROUTINE ran_init( length )
	160
	161	USE kinds
	162
	163	IMPLICIT NONE
	164
[1682]	165	INTEGER(isp), INTENT(IN) :: length !<
[1400]	166
[1682]	167	INTEGER(isp), PARAMETER:: hg=huge(1_isp) !<
	168	INTEGER(isp), PARAMETER:: hgm=-hg !<
	169	INTEGER(isp), PARAMETER:: hgng=hgm-1 !<
[1400]	170
[1682]	171	INTEGER(isp) :: new !<
	172	INTEGER(isp) :: j !<
	173	INTEGER(isp) :: hgt !<
[1400]	174
	175	IF ( length < lenran ) RETURN !- Simply return if enough space is already allocated.
	176
	177	hgt = hg
	178
	179	!- The following lines check that kind value isp is in fact a 32-bit integer
	180	!- with the usual properties that we expect it to have (under negation and wrap-around addition).
	181	!- If all of these tests are satisfied, then the routines that use this module are portable,
	182	!- even though they go beyond Fortran 90's integer model.
	183
	184	IF ( hg /= 2147483647 ) CALL ran_error('ran_init: arith assump 1 fails')
	185	IF ( hgng >= 0 ) CALL ran_error('ran_init: arith assump 2 fails')
	186	IF ( hgt+1 /= hgng ) CALL ran_error('ran_init: arith assump 3 fails')
	187	IF ( not(hg) >= 0 ) CALL ran_error('ran_init: arith assump 4 fails')
	188	IF ( not(hgng) < 0 ) CALL ran_error('ran_init: arith assump 5 fails')
	189	IF ( hg+hgng >= 0 ) CALL ran_error('ran_init: arith assump 6 fails')
	190	IF ( not(-1_isp) < 0 ) CALL ran_error('ran_init: arith assump 7 fails')
	191	IF ( not(0_isp) >= 0 ) CALL ran_error('ran_init: arith assump 8 fails')
	192	IF ( not(1_isp) >= 0 ) CALL ran_error('ran_init: arith assump 9 fails')
	193
	194	IF ( lenran > 0) THEN !- Reallocate space, or ...
	195
	196	ranseeds => reallocate( ranseeds, length, 5)
	197	ranv => reallocate( ranv, length-1)
	198	new = lenran+1
	199
	200	ELSE !- allocate space.
	201
	202	ALLOCATE(ranseeds(length,5))
	203	ALLOCATE(ranv(length-1))
	204	new = 1 !- Index of first location not yet initialized.
	205	amm = nearest(1.0_wp,-1.0_wp)/hgng
	206	!- Use of nearest is to ensure that returned random deviates are strictly lessthan 1.0.
	207	IF (ammhgng >= 1.0 .or. ammhgng <= 0.0) &
	208	CALL ran_error('ran_init: arith assump 10 fails')
	209
	210	END IF
	211
	212	!- Set starting values, unique by seq and vector component.
	213	ranseeds(new:,1) = seq
	214	ranseeds(new:,2:5)=spread(arth(new,1,size(ranseeds(new:,1))),2,4)
	215
	216	DO j=1,4 !- Hash them.
	217	CALL ran_hash(ranseeds(new:,j), ranseeds(new:,j+1))
	218	END DO
	219
	220	WHERE (ranseeds (new: ,1:3) < 0) &
	221	ranseeds(new: ,1:3)=not(ranseeds(new: ,1:3)) !- Enforce nonnegativity.
	222
	223	WHERE (ranseeds(new: ,4:5) == 0) ranseeds(new: ,4:5)=1 !- Enforce nonzero.
	224
	225	IF (new == 1) THEN !- Set scalar seeds.
	226
	227	iran0 = ranseeds(1,1)
	228	jran0 = ranseeds(1,2)
	229	kran0 = ranseeds(1,3)
	230	mran0 = ranseeds(1,4)
	231	nran0 = ranseeds(1,5)
	232	rans = nran0
	233
	234	END IF
	235
	236	IF (length > 1) THEN !- Point to vector seeds.
	237
	238	iran => ranseeds(2:,1)
	239	jran => ranseeds(2:,2)
	240	kran => ranseeds(2:,3)
	241	mran => ranseeds(2:,4)
	242	nran => ranseeds(2:,5)
	243	ranv = nran
	244
	245	END IF
	246
	247	lenran = length
	248
	249	END SUBROUTINE ran_init
	250
	251	!------------------------------------------------------------------------------!
	252	! Description:
	253	! ------------
[1682]	254	!> User interface to release the workspace used by the random number routines.
[1400]	255	!------------------------------------------------------------------------------!
	256	SUBROUTINE ran_deallocate
	257
	258	IF ( lenran > 0 ) THEN
	259
	260	DEALLOCATE(ranseeds, ranv)
	261	NULLIFY(ranseeds, ranv, iran, jran, kran, mran, nran)
	262	lenran = 0
	263
	264	END IF
	265
	266	END SUBROUTINE ran_deallocate
	267
	268	!------------------------------------------------------------------------------!
	269	! Description:
	270	! ------------
[1682]	271	!> User interface for seeding the random number routines.
	272	!> Syntax is exactly like Fortran 90's random_seed routine,
	273	!> with one additional argument keyword: random_sequence, set to any integer
	274	!> value, causes an immediate new initialization, seeded by that integer.
[1400]	275	!------------------------------------------------------------------------------!
	276	SUBROUTINE random_seed_parallel( random_sequence, state_size, put, get )
	277
	278	IMPLICIT NONE
	279
[1682]	280	INTEGER(isp), OPTIONAL, INTENT(IN) :: random_sequence !<
	281	INTEGER(isp), OPTIONAL, INTENT(OUT) :: state_size !<
[1400]	282
[1682]	283	INTEGER(isp), DIMENSION(:), OPTIONAL, INTENT(IN) :: put !<
	284	INTEGER(isp), DIMENSION(:), OPTIONAL, INTENT(OUT) :: get !<
[1400]	285
	286	IF ( present(state_size) ) THEN
	287
	288	state_size = 5 * lenran
	289
	290	ELSE IF ( present(put) ) THEN
	291
	292	IF ( lenran == 0 ) RETURN
	293
	294	ranseeds = reshape( put,shape(ranseeds) )
	295
	296	WHERE (ranseeds(:,1:3) < 0) ranseeds(: ,1:3) = not(ranseeds(: ,1:3))
	297	!- Enforce nonnegativity and nonzero conditions on any user-supplied seeds.
	298
	299	WHERE (ranseeds(:,4:5) == 0) ranseeds(:,4:5) = 1
	300
	301	iran0 = ranseeds(1,1)
	302	jran0 = ranseeds(1,2)
	303	kran0 = ranseeds(1,3)
	304	mran0 = ranseeds(1,4)
	305	nran0 = ranseeds(1,5)
	306
	307	ELSE IF ( present(get) ) THEN
	308
	309	IF (lenran == 0) RETURN
	310
	311	ranseeds(1,1:5) = (/ iran0,jran0,kran0,mran0,nran0 /)
	312	get = reshape( ranseeds, shape(get) )
	313
	314	ELSE IF ( present(random_sequence) ) THEN
	315
	316	CALL ran_deallocate
	317	seq = random_sequence
	318
	319	END IF
	320
	321	END SUBROUTINE random_seed_parallel
	322
	323	!------------------------------------------------------------------------------!
	324	! Description:
	325	! ------------
[1682]	326	!> DES-like hashing of two 32-bit integers, using shifts,
	327	!> xor's, and adds to make the internal nonlinear function.
[1400]	328	!------------------------------------------------------------------------------!
	329	SUBROUTINE ran_hash_v( il, ir )
	330
	331	IMPLICIT NONE
	332
[1682]	333	INTEGER(isp), DIMENSION(:), INTENT(INOUT) :: il !<
	334	INTEGER(isp), DIMENSION(:), INTENT(INOUT) :: ir !<
[1400]	335
[1682]	336	INTEGER(isp), DIMENSION(size(il)) :: is !<
[1400]	337
[1682]	338	INTEGER(isp) :: j !<
[1400]	339
	340	DO j=1,4
	341
	342	is = ir
	343	ir = ieor( ir, ishft(ir,5) ) + 1422217823
	344	ir = ieor( ir, ishft(ir,-16) ) + 1842055030
	345	ir = ieor( ir, ishft(ir,9) ) + 80567781
	346	ir = ieor( il, ir )
	347	il = is
	348	END DO
	349
	350	END SUBROUTINE ran_hash_v
	351
	352	!------------------------------------------------------------------------------!
	353	! Description:
	354	! ------------
[1682]	355	!> User interface to process error-messages
	356	!> produced by the random_number_parallel module
[1400]	357	!------------------------------------------------------------------------------!
	358	SUBROUTINE ran_error(string)
	359
[1682]	360	CHARACTER(LEN=*), INTENT(IN) :: string !<
[1400]	361
	362	write (,) 'Error in module random_number_parallel: ',string
	363
	364	STOP 'Program terminated by ran_error'
	365
	366	END SUBROUTINE ran_error
	367
	368	!------------------------------------------------------------------------------!
	369	! Description:
	370	! ------------
[1682]	371	!> Reallocates the generators state space "ranseeds" to vectors of size length.
[1400]	372	!------------------------------------------------------------------------------!
	373	FUNCTION reallocate_iv( p, n )
	374
[1682]	375	INTEGER(isp), DIMENSION(:), POINTER :: p !<
	376	INTEGER(isp), DIMENSION(:), POINTER :: reallocate_iv !<
[1400]	377
[1682]	378	INTEGER(isp), INTENT(IN) :: n !<
[1400]	379
[1682]	380	INTEGER(isp) :: nold !<
	381	INTEGER(isp) :: ierr !<
[1400]	382
	383	ALLOCATE(reallocate_iv(n),stat=ierr)
	384
	385	IF (ierr /= 0) CALL &
	386	ran_error('reallocate_iv: problem in attempt to allocate memory')
	387
	388	IF (.not. associated(p)) RETURN
	389
	390	nold = size(p)
	391
	392	reallocate_iv(1:min(nold,n)) = p(1:min(nold,n))
	393
	394	DEALLOCATE(p)
	395
	396	END FUNCTION reallocate_iv
	397
	398	FUNCTION reallocate_im( p, n, m )
	399
[1682]	400	INTEGER(isp), DIMENSION(:,:), POINTER :: p !<
	401	INTEGER(isp), DIMENSION(:,:), POINTER :: reallocate_im !<
[1400]	402
[1682]	403	INTEGER(isp), INTENT(IN) :: m !<
	404	INTEGER(isp), INTENT(IN) :: n !<
[1400]	405
[1682]	406	INTEGER(isp) :: mold !<
	407	INTEGER(isp) :: nold !<
	408	INTEGER(isp) :: ierr !<
[1400]	409
	410	ALLOCATE(reallocate_im(n,m),stat=ierr)
	411
	412	IF (ierr /= 0) CALL &
	413	ran_error('reallocate_im: problem in attempt to allocate memory')
	414
	415	IF (.not. associated(p)) RETURN
	416
	417	nold = size(p,1)
	418	mold = size(p,2)
	419
	420	reallocate_im(1:min(nold,n),1:min(mold,m)) = &
	421	p(1:min(nold,n),1:min(mold,m))
	422
	423	DEALLOCATE(p)
	424
	425	END FUNCTION reallocate_im
	426
	427	!------------------------------------------------------------------------------!
	428	! Description:
	429	! ------------
[1682]	430	!> Reallocates the generators state space "ranseeds" to vectors of size length.
[1400]	431	!------------------------------------------------------------------------------!
	432	FUNCTION arth_i(first,increment,n)
	433
[1682]	434	INTEGER(isp), INTENT(IN) :: first !<
	435	INTEGER(isp), INTENT(IN) :: increment !<
	436	INTEGER(isp), INTENT(IN) :: n !<
[1400]	437
[1682]	438	INTEGER(isp), DIMENSION(n) :: arth_i !<
[1400]	439
[1682]	440	INTEGER(isp) :: k !<
	441	INTEGER(isp) :: k2 !<
	442	INTEGER(isp) :: temp !<
[1400]	443
[1682]	444	INTEGER(isp), PARAMETER :: npar_arth=16 !<
	445	INTEGER(isp), PARAMETER :: npar2_arth=8 !<
[1400]	446
	447	IF (n > 0) arth_i(1) = first
	448
	449	IF (n <= npar_arth) THEN
	450
	451	DO k=2,n
	452	arth_i(k) = arth_i(k-1)+increment
	453	END DO
	454
	455	ELSE
	456
	457	DO k=2,npar2_arth
	458	arth_i(k) = arth_i(k-1) + increment
	459	END DO
	460
	461	temp = increment * npar2_arth
	462	k = npar2_arth
	463
	464	DO
	465	IF (k >= n) EXIT
	466	k2 = k + k
	467	arth_i(k+1:min(k2,n)) = temp + arth_i(1:min(k,n-k))
	468	temp = temp + temp
	469	k = k2
	470	END DO
	471
	472	END IF
	473
	474	END FUNCTION arth_i
	475
	476	END MODULE random_generator_parallel

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